Volvo Penta 230, Workshop Manual

Page 1: ...Engine 230 250 251DOHC AQ131 AQ151 AQ171 Workshop Manual 2 0 C ...

Page 2: ......

Page 3: ...hauling the heat exchanger 48 Overhauling the sea water pump 49 Check the thermostat 49 4E Overhauling the valve system 50 Overhauling the valve system 230 250 AQ131 AQ151 50 Adjusting the valves 230 250 AQ131 AQ151 59 Valve system 251DOHC AQ171 Technical Description 61 Overhauling the valve system 251DOHC AQ171 63 4F Installing the toothed belt 71 Installing the toothed belt 230 250 AQ131 AQ151 7...

Page 4: ...nta prod ucts or product versions contained in the contents list Ensure that the correct workshop literature is being used Read the safety information and the Workshop Manual General Information and Repair Instruc tions carefully before starting work Important In this book and on the engine you will find the follow ing special warning symbols WARNING If these instructions are not fol lowed there i...

Page 5: ...n from batteries are easily inflammable and explosive Smoking is prohibited Ensure that ventilation is good and that the necessary safety precautions have been taken before carrying out welding or grinding work Always have a fire extinguisher to hand in the work place Store oil and fuel soaked rags and fuel and oil filters safely In certain conditions oil soaked rags can spontaneously ignite Used ...

Page 6: ...ting equipment such as se cured blocks are being used Even where lift ing equipment is being used it is best to carry out the work with two people one to operate the lifting equipment and the other to ensure that components are not trapped and damaged when being lifted When working on board en sure that there is sufficient space to remove components without danger of injury or dam age Components i...

Page 7: ...olvo Penta is continuously developing their prod ucts We therefore reserve the right to make changes All the information contained in this book is based on product data available at the time of going to print Any essential changes or modifications in troduced into production or updated or revised ser vice methods introduced after the date of publication will be provided in the form of Service Bull...

Page 8: ...an be malfunction or a shorter operational life Our joint responsibility Each engine consists of many connected systems and components If a component deviates from its technical specification the environmental impact of an otherwise good engine may be increased significantly It is therefore vital that wear tolerances are main tained that systems that can be adjusted are adjusted properly and that ...

Page 9: ...zes in the engines To ensure service work is correctly carried out it is important that the correct sealant and locking fluid type is used on the joint where the agents are re quired In this Volvo Penta Service Manual the user will find that each section where these agents are applied in production states which type was used on the engine During service operations use the same agent or an alternat...

Page 10: ...n 230 replaced AQ131 250 replaced AQ151and 251DOHC replaced AQ171 250 AQ151 and 251DOHC AQ171 are equipped with an oil cooler 230 AQ131 has a single carburettor and the others have twin carburettors The exhaust system has seawater cooled exhaust pipes 230 AQ131 and 250 AQ151 models have an overhead camshaft while 251DOHC AQ171 has double overhead camshafts with hydraulic valve lift ers 251DOHC AQ1...

Page 11: ...em The fresh water cooling system thermostat closed The fresh water cooling system thermostat open 1 Sea water filter 2 Heat exchanger 3 Sea water pump 4 Oil cooler 5 Bypass 6 Thermostat house 7 Circulation pump The Cooling System ...

Page 12: ...ng System The engine lubricating system from strainer to the main gallery The engine lubricating system from the main gallery to the lubricating points 1 Main gallery 2 Oil pump 3 Return line 4 Oil cooler 5 Oil filter ...

Page 13: ...ometer Boat loaded abnormally Growth on boat bottom and sterndrive Damaged propeller Clogged cooling water intake oil cooler 250 251DOHC AQ151 AQ171 waterjackets Damaged impeller or thermostat Too low coolant level in expansion tank Wrong fuel quality in relation to timing Toothed belt faulty or not adjusted properly Engine does not start Engine stops Engine does not reach op erating speed at full...

Page 14: ... cruising speed 3 33 r s 200 rpm lower than the max speed obtained Compression ratio 9 7 1 Compression pressure at starter motor speed1 10 12 kp cm2 142 170 psi Number of cylinders 4 in line Bore 96 mm 3 7795 Stroke 86 mm 3 3858 Swept volume displacement 2 49 dm3 151 9 in3 Weight excluding water and oil approx 250 Kilos 551 2 lbs Idling speed 15 r s 900 rpm General Type designation 251DOHC AQ171 T...

Page 15: ...02 3 803 3 Maximum weight difference between pistons in the same engine is 16 grams 0 56 oz 4 See the spare parts catalog for all the products Piston rings Piston ring end gap oil scraper ring 0 30 0 60 mm 0 0118 0 0236 Piston ring end gap compression ring 0 30 0 55 mm 0 0118 0 0217 Oversize piston rings 1 0 3 mm 0 0118 Oversize piston rings 2 0 6 mm 0 0236 Compression rings The upper ring is chro...

Page 16: ...25 mm 1 2681 1 2697 Oversize 2 32 46 32 50 mm 1 2780 1 2795 The main bearings are available in two makes The upper and lower main bearing shell on the same pivot must be of the same make In production matched crankshaft bearing shells are used The bearing shells are color coded red yellow and blue They are matched in accordance with one of the following alternatives Alternative 1 Two yellow marked...

Page 17: ... 975 47 000 mm 1 849 1 850 Middle bearing diameter 43 025 43 050 mm 1 694 1 695 Rear bearing diameter 42 925 42 950 mm 1 690 1 691 Radial clearance 0 020 0 075 mm 0 0008 0 0030 Axial clearance end play 0 20 0 46 mm 0 0079 0 0181 Intermediate shaft bearing diameter in block Front 47 020 47 050 mm 1 851 1 852 Middle 43 070 43 100 mm 1 696 1 697 Rear 42 970 43 000 mm 1 692 1 693 Changing the bearings...

Page 18: ...prings 230 250 AQ131 AQ151 Length unloaded 45 0 mm 1 772 Length loaded 285 325 N 28 5 32 5 kp 38 0 mm 1 496 Length loaded 725 805 N 72 5 80 5 kp 27 0 mm 1 063 Valves 251DOHC AQ171 Inlet Disc diameter 34 5 mm 1 358 Stem diameter 6 955 6 970 mm 0 2738 0 2744 Valve seat angle 44 5 Cylinder block seat angle 45 Seat width in cylinder head 1 3 1 9 mm 0 0512 0 0748 Exhaust Disc diameter 31 5 mm 1 240 Ste...

Page 19: ...ssure at 33 33 r s 2000 rpm hot engine 2 5 6 0 kp cm2 35 85 psi Lubricating oil alternative 1 Volvo Penta lubricating oil for gasoline engines Lubricating oil alternative 2 Lubricating oil SG Viscosity SAE 20 W 50 Oil filter Type Full flow filter Lubricating oil pump Axial clearance 0 02 0 12 mm 0 0008 0 0047 Radial clearance excluding bearing clearance 0 02 0 09 mm 0 0008 0 0035 Gear backlash exc...

Page 20: ...DOHC AQ171 AQ171A AQ171B 251DOHC Type Down draught Down draught Designation Model 44 PAI 5 6 Model 44 PAI 7 Venturi 32 32 Main jet 147 147 Idling jet 65 60 Air jet 190 200 Needle valve 1 7 1 7 Float weight in grams oz s 7 3 0 26 7 3 0 26 Acceleration jet 70 70 Econostat jet Electrical system Battery Grounding Negative Voltage 12 Volts Capacity 60 Ah Specific weight of the electrolyte Fully charged...

Page 21: ...he torque values are valid for bolts and nuts being well oiled prior to installation Parts having been washed should be oiled prior to the assembly Tightening torque for cylinder head bolts The cylinder head To be tightened in stages 1 20 Nm 2 0 kpm 15 ft lbs 2 40 Nm 4 0 kpm 29 ft lbs 3 Angle tighten through 120 in one operation Replace the cylinder head bolts if they show signs of being stretched...

Page 22: ...in the flywheel housing Drift for the installation of the seal in the flywheel housing Drift for the changing of valve guides 251DOHC AQ171 Drift for the changing of valve guides 251DOHC AQ171 Drift for the changing of valve guides 251DOHC AQ171 Reamer valve guides 251DOHC AQ171 Cylinder head fixture 251DOHC AQ171 Stand fixture Installation tool inlet valve seat 251DOHC AQ171 Installation tool exh...

Page 23: ... tool for the removal and assembly of the camshaft AQ131 AQ151 230 250 9995022 2 Tool for depressing valve depressors AQ131 AQ151 230 250 9995025 5 Installation tool for the intermediate shaft seal 9995026 3 9995027 1 Pair of pliers for adjustment shims AQ131 AQ151 230 250 Drift for the installation of valve guides inlet AQ131 AQ151 230 250 9988452 0 Digital probe tester ...

Page 24: ...for valve seats exhaust AQ131 AQ151 230 250 Reamer valve guides AQ131 AQ151 230 250 Drift for the installation of sealing in the crankshaft rear end Removal tool for the crankshaft front seal Counterhold for crankshaft pulley Drift for the removal and installation of bushing in the connecting rod Tensioning tool for the toothed belt AQ171 251DOHC 9995028 9 Drift for the installation of valve guide...

Page 25: ...1 and the later type 2 for version refer to wiring diagrams Both the in strumentation types are equipped with two 8 A fuses for the system voltage key switch in ignition posi tion and start voltage key switch in start position Instrumentation type 2 is equipped with 2 connectors for extra power outputs for accessories One is fused via the 8 A fuse for system voltage and has a maximum permissible v...

Page 26: ...ument lighting 9 Fuse 8 A 10 Fuse 8 A 11 Generator 12 Starter motor 13 Connector engine instrumentation 14 Automatic fuse 40A 15 Main switch option 16 Battery 17 Temperature sensor 18 Oil pressure sensor 19 Distributor 20 Ignition coil 21 Relay 22 Resistor Cable cross sections AWG mm2 16 1 5 13 2 5 10 6 0 8 10 0 Cable colour code SB Black PU Purple LBN Light brown R Red GR Grey LBL Light blue R Y ...

Page 27: ...25 AQ131 AQ151 230 250 ALT 1 ...

Page 28: ...Connector instrument lighting accessory 13 Connector power output maximum 20 A 14 Connector power output maximum 5 A main panel flying bridge panel 15 Connector engine instrumentation 16 Automatic fuse 40A 17 Main switch option 18 Battery 19 Temperature sensor 20 Oil pressure sensor 21 Distributor 22 Ignition coil 23 Starter motor 24 Relay 25 Generator 26 Resistor Cable cross sections AWG mm2 16 1...

Page 29: ...27 230 250 ALT 2 ...

Page 30: ...ernator 12 Starter motor 13 Terminal block 14 Automatic fuse 40 Amp 15 Main switch optional 16 Battery optional 17 Temp sender 18 Oil pressure sender 19 Distributor 20 Electronic ignition unit 21 Relay 22 Resistor 23 Impulse sender ignition unit 24 Ground screw 25 Solenoid valve Cable cross sections AWG mm2 16 1 5 13 2 5 10 6 0 8 10 0 Cable colour code SB Black PU Purple LBN Light brown R Red GR G...

Page 31: ...29 AQ171 251DOHC ALT 1 ...

Page 32: ... Fuse 8 A 9 Fuse 8 A 10 Contact terminal neutral position switch option accessory 11 Contact terminal safety switch accessory 12 Connector instrument lighting accessory 13 Connector power output maximum 20 A 14 Connector power output maximum 5 A main panel flying bridge panel 15 Connector engine instrumentation 16 Automatic fuse 40A 17 Main switch option 18 Battery 19 Temperature sensor 20 Oil pre...

Page 33: ...31 251DOHC ALT 2 ...

Page 34: ...ace the gasket Check the throttle shaft clearance Intake manifold loose X X X X Tighten the manifold and replace the gasket Acceleration jet clogged X Blow the jet clean Throttle does not open X X Adjust the throttle linkage Wrong jet X X X Check the marking in Technical Data Bad compression X X X Take a compression test and then act according to results Worn spark plugs Change the spark plugs See...

Page 35: ...nd check it for leakage Should the float leak the float level will not be correct The weight of the float should be 7 3 grams 0 26 oz s Remove the emulsion jet 1 and the acceleration jet 2 NOTE Don t forget the gasket Check and blow clean with compressed air Replace worn or dam aged parts if necessary 4 Remove the idle jet 1 and the main jet holder 2 Remove the jet from its holder Clean the jets w...

Page 36: ...n the thrust rod into the lever 6 Install the idle jet 1 the main jet 2 and the mixture screw 3 NOTE The copper washer on the main jet Install the emulsion jet 4 the acceleration jet 5 and the gasket 6 Put the float 7 into the float housing and add a new gasket 8 and tighten the top cover of the carburetor to the carburetor housing Remove the nut 9 and the levers to be able to replace the spring 1...

Page 37: ...ORTANT Locate the plate the way the illustra tion indicates AQ131C AQ131D earlier manufacture Late version of AQ131C AQ131D 230 the text turned the right way up 9 AQ131C AQ131D 230 These engines are equipped with a new plate NOTE The plate is located with the text upside down earlier manufacture The plate is installed between 2 gaskets On engines of later manufacture the text is turned the right w...

Page 38: ...ws out from both the carbu retors jets at the same time and that a hissing sucking sound can be heard from the carburetors Fine adjust if necessary 16 Connect the fuel pipe to the fuel pump Tool width 12 mm 13 Check that the idle and air screws are set as per point 6 Then place the butterfly valve shaft between the carburetors and fit them to the intake manifold 230 AQ131 does not have a separate ...

Page 39: ...at the spindle 7 turns and opens a fuel and an air channel in the carbur etor This way the engine gets an additional fuel air supply Start with hot engine When the engine temperature is above 50 C 122 F the shut off valve 3 is closed The vacuum in the vacuum housing 4 ceases and the rod 6 returns by spring pressure to its original position If the engine speed is increased while the engine is cold ...

Page 40: ...ith power amplifier The ignition coil is of the mod ern dry type and is replaceable Ignition position sender 19 The crankshaft position sender is located at the rear of the engine and registers the position of the flywheel by reading the teeth machined holes in the circumference of the flywheel The distributor 20 The flat distributor is mounted at the rear of the engine The only task of the distri...

Page 41: ...me a tooth passes by It also provides the control unit with information when each of the 2 big teeth pass by Thus the position of the upper dead center is known since it is positioned 11 teeth after the long tooth The function 23 Half a turn before each explosion cycle the con trol unit is calculating a very exact pre ignition going out from the speed of the engine There are 63 op timized engine s...

Page 42: ...t not needed speed control 7 Not used 3 ground 8 Not used 3 ground 9 Ignition coil primary winding 10 Ignition coil primary winding 11 Ignition coil secondary winding 12 Radio suppression connection Trouble shooting A The engine does not start see para 26 to 33 B The engine is running rough starts with difficulty low output See para 34 to 40 C The engine starts but does not continue to run See par...

Page 43: ...tch the ignition on Con nect a voltmeter to check the voltage between 3 and ground The voltage should be at least 9 5 Volts Check the ground connection 28 Measure the resistance between 2 and ground The resistance should be 0 Ohm The ground con nection is a bolt behind and below the alternator Should the resistance be higher than 0 Ohm Check the ground connection and the wire harness Checking spar...

Page 44: ... lows 14 17r s 850 rpm 10 2 25 r s 1500 rpm 14 2 58 33 r s 3500 rpm 23 2 75 r s 4500 rpm 24 2 91 67 r s 5500 rpm 31 2 Checking the speed limit 40 Check using a tachometer that the engine s speed does not increase above 6200 100 rpm If the speed increases above 6200 100 rpm then the control unit must be replaced Checking the toothed belt against the markings 41 Check that the timing belt is correct...

Page 45: ...43 Changing the rotor 251DOHC AQ171 46 Remove the distributor cap 3 screws Tool width 8 mm 47 Remove and replace the rotor Re install the dis tributor cap ...

Page 46: ...rom the spark plugs 50 251DOHC AQ171 Remove the protective cover over the camshaft gear wheels Tool width 10 mm 51 Remove the bolts from the heat exchanger bracket Tool width 12 mm 52 Remove the screws from the thermostat housing against the heat exchanger Tool width 12 mm NOTE Take care of the spacer sleeves Not all manufactures 53 Remove the hose clamp and pull off the cooling water hose from th...

Page 47: ...x haust manifold and the oil cooler Tool width 10 mm 56 Remove the exhaust manifold Tool width 13 mm 57 Pull off the hose 1 from the carburetor and re move the screw holding the oil dipstick tube Tool width 1 2 58 Remove the fuel pipe from the fuel pump Tool width 12 mm 59 251DOHC AQ171 Pull off the vacuum hoses 1 from the intake manifold and the cold starting de vice as well as the connection 2 f...

Page 48: ...cessary to loosen the lower screws a few turns only 61 Remove the temp sender wire Tool width 3 8 62 Remove the cooling water pipes from the sea water pump 63 Remove the sea water pump Tool width 10 mm 64 Remove the timing gear cover Tool widths Al len key 6 mm and hexagonal 10 mm 65 Remove the alternator and the V belt Tool widths 13 and 16 mm ...

Page 49: ...MPORTANT Do not turn the crankshaft or the camshaft while the toothed belt is re moved The pistons can hit the valves 68 230 250 AQ131 AQ151 Bring the engine to TDC as under paragr 66 Then ease off the nut of the belt tensioning roller Tool width 17 mm Pull the belt and insert a 3 mm drill in the hole of the tension ing device Then remove the belt NOTE Do not turn either the crankshaft or the cam ...

Page 50: ...1 on model 251DOHC AQ171 Otherwise the same reconditioning method as for the heat ex changer applies 75 Lift out the cooling element and the insulating rubber mat from the housing Pull the cooling ele ment straight upwards If necessary use a screw driver to pry carefully Clean all parts thoroughly 76 Remove the strainer housing and the tube con nection from the heat exchanger housing Tool width 10...

Page 51: ... little at the time NOTE The cover will be pressed down approx imately 5 mm 0 25 Allen key 4 mm The sea water pump 83 Remove the cover on the sea water pump and use pliers to pull out the impeller Take care of the key Push out the seal ring Install a new seal ring Turn the seal lip facing the impeller Grease the seal ring abundantly and carefully push the shaft into the seal ring Insert the key an...

Page 52: ... part no 9995034 7 NOTE Remove the washer behind the gear wheel 88 Remove the middle camshaft cap Tool width 1 2 89 Install special tool part no 9995021 4 on the camshaft Use the cap nut The tool is keeping ten sion on the camshaft Remove the remaining 4 cam shaft caps 90 Remove the sealing 1 from the camshaft as well as the plug in the opposite end Back off the special tool releasing the camshaft...

Page 53: ...e 96 Clean the cylinder head and sealing surface Use a metal ruler and feeler gauge The warp must not exceed 0 5 mm 0 0197 lengthwise and 0 25 mm 0 0098 diagonally IMPORTANT The cylinder head cannot be machined if the warp is greater than 1 00 mm 0 394 lengthwise or 0 5 mm 0 0197 diag onally Cylinder head height new 146 1 mm 5 75197 Cylinder head height min after reworking 145 6 mm 5 73228 Reworki...

Page 54: ... direction of the combustion chamber Check to make sure that the valve guide has not been subject to seizing 100 Valve guides in the standard size are available as spare parts 101 Press in new valve guides The cylinder head should be at room temperature Use drift part no 9995027 1 for the intake and part no 9995028 9 for the exhaust Press the valve guides till the drift touches the cylinder head T...

Page 55: ...in order to provide a hold for the chisel Make sure not to damage the cylinder head 105 Knock out the valve seat with a long drift through intake port the cylinder head 106 Check the position of the valve seat Should the seat location be damaged it has to be reamed milled to the closest oversize Then measure the valve seat diameter Use an internal micrometer 104 Crack the valve seat with a chisel ...

Page 56: ... carbon dioxide snow dry ice or its equivalent Use protective gloves Install the valve seat in the cylinder head This sequence must be done quickly and at least within 3 to 4 seconds This depends on the fact that the components must have their predetermined temperature at the time of assembly Then check the fit of the seat The seat should be fully home and held in position Should the seat not be h...

Page 57: ...fered surface of the valve seat the valve does not seat the valve must be reground and checked until a completely satisfactory result has been obtained 115 Check that the clearance of the adjustment washer in the valve tappet is not too big If there are wear marks on the flat surface it should be re placed The clearance between the adjustment washer and the valve tappet should be 0 009 0 068 mm 0 ...

Page 58: ...park plug thread enters properly in order not to damage the cylinder head thread Tightening torque 25 30 Nm 2 5 3 0 kpm 18 22 ft lbs 120 Oil and install the valve tappets along with the adjustment washers and in the same location as earlier 121 Oil the bearing halves the camshaft lobes the valve tappets and the adjustment washers and insert the camshaft The guide pin for the toothed belt wheel sho...

Page 59: ... head with a gasket com pound Make sure that the sealing is properly aligned prior to the tightening of the front bearing cap Then remove the special tool 126 Oil and tighten the last bearing cap Now tight en all the nuts with a torque wrench Tightening torque 20 Nm 2 0 kpm 15 ft lbs 127 Install the camshaft gear wheel and the spacer washer Use counterhold part no 9995034 7 Tightening torque 50 Nm...

Page 60: ...bolts a maxi mum of 5 times In case of uncertainty always re place the bolts with new ones 129 Set the piston for cylinder no 1 at T D C Check to make sure that the contact surface of the engine block is properly cleaned and install a new cylinder head gasket 130 Set the camshaft in position T D C for cylinder no 1 131 Install the cylinder head 133 Oil the threads of the cylinder head bolts and in...

Page 61: ...stall special tool part no 9995022 2 and press down the valve tappets Tighten the tool spindle and adjust until the groove of the valve lifter is above the edge and thus accessible with a pair of pliers 137 Use special tool part no 9995026 3 pair of pli ers to lift out the washer 138 Measure the thickness of the washer with a mi crometer Calculate the thickness of the washer giving the correct cle...

Page 62: ...an be complemented if necessary by ordering from the Volvo Penta Parts Department The complete kit part no 884516 4 contains the following parts Part No Qty Designation Thickness mm inch 463551 6 Adjustment shim 3 55 0 13976 463552 6 Adjustment shim 3 60 0 14173 463553 6 Adjustment shim 3 65 0 14370 463554 6 Adjustment shim 3 70 0 14567 463555 6 Adjustment shim 3 75 0 14764 463556 12 Adjustment sh...

Page 63: ... special camshaft carri er fitted on the cylinder head The seal between the camshaft carrier and the cylinder head is done in two ways The spark plug wells are sealed by four O rings between the camshaft carrier and cylinder head The sealing of the flat surfaces between the camcylinder head is done using a sealing compound Loctite The valve cover gasket is in two parts One seals against the spark ...

Page 64: ...oil pressure is greater than the oil pressure in the hydraulic valve tappet the oil passes the check valve the ball The camshaft presses the valve tappet down The oil pressure in the valve tappet cylinder then be comes greater than the engine s the check valve closes and the hydraulic valve tappet works as one unit The valve tappet back on the camshaft s base circle The engine s oil pressure is gr...

Page 65: ...nsure that the correct order is main tained 146A Check the valve tappets for any wear Meas ure if necessary Hydraulic valve lifter measurement A External diameter mm in 35 1 378 B External height mm in 26 1 024 Distance to top of valve tappet C 1 Unloaded mm in 18 40 0 724 C 2 Compressed mm in 16 15 0 636 143 Remove the camshaft bearing caps Tool width 1 2 The caps are numbered from 1 to 10 NOTE N...

Page 66: ... parts 147 Remove the 5 nuts which attach the camshaft carrier to the cylinder head Tool width 1 2 Then lift out the camshaft carrier NOTE Remove the O rings between the cylinder head and the camshaft carrier later production 151 Remove the valve seals from the intake valves and then the lower washer 152 Clean the cylinder head and sealing surface Use a metal ruler and a feeler gauge The warp must...

Page 67: ...new valve and new valve guide intake 0 030 0 060 mm 0 00118 0 00236 exhaust 0 040 0 070 mm 0 00157 0 00276 Maximum clearance allowed with new valve and old valve guide is 0 15 mm 0 0059 for intake as well as for exhaust 155 Place the cylinder head in special tool part no 884979 6 and hold it with 2 screws M12 156 Use special tool part no 884959 0 to start pressing out the valve guide Press until t...

Page 68: ...n principle be changed in accordance with paragraphs 103 108 on pages 53 and 54 Special tool part no 884960 6 for intake and part no 884961 4 for exhaust 161 IMPORTANT The exhaust valves are Stellite coated and therefore cannot be machined They can only be lapped to fit by using grinding compound If they are machined the Stellite coating is removed and the heat protection of the valve is reduced 1...

Page 69: ...alve will not seal the valve has to be lapped further and checked once more until a correct result has been obtained Assembling the cylinder head 165 Place the lower valve spring washer in the cy linder head Oil and install the valve Then install the seal on the intake valves only 166 Install 1 The valve spring 2 The upper valve spring retainer 3 The valve lock Use the valve spring compressor NOTE...

Page 70: ...bolt If the waist is elongated then the bolt has to be replaced by a new one The bolts can be re used 5 times at the most If uncertain replace all bolts 171 Tighten the bolts in sequence and in steps See the illustration Tool width 14 mm 1 20 Nm 2 0 kpm 15 ft lbs 2 40 Nm 4 0 kpm 30 ft lbs 3 angle tightening through 120 172 Place the O rings in their positions on the cylin der head NOTE On engines ...

Page 71: ...in the camshaft carrier is not damaged Replace if ne cessary 176 Grease the seal ring and install it carefully on the camshaft NOTE Turn the smooth side facing outwards to wards the front 177 Install the camshaft gears on the camshaft Use counterhold part no 9995034 7 Tightening torque 50 Nm 5 0 kpm 36 ft lbs 178 Place the camshafts in the camshaft carriers so that the front lobes No 1 are turned ...

Page 72: ... the crankshaft or the camshaft The pistons will hit the valves 180 Install the nuts and tighten them with a torque of 20 Nm 2 0 kpm 15 ft lbs Tool width 1 2 Tighten alternatingly and in sequence NOTE Also tighten the nuts in the middle IMPORTANT Do not turn the crankshaft or the camshaft The pistons might hit the valves 181 Install new gaskets on the camshaft carrier The gasket in the middle of t...

Page 73: ...olts Then make sure that the marking of the camshaft gear lines up with the plate marking Note not all engines have the marked plate 186 Check the condition of the toothed belt NOTE Grease or oil must not be on the belt Then adjust the markings of the belt as follows Two lines against the marking of the crankshaft guide plate and one line against the marking of the intermediate wheel The last mark...

Page 74: ...ees This is in order to remove the slack between the belt wheels NOTE Do not turn the crankshaft anti clockwise This will cause the belt to jump over giving an incor rect setting 190 Back off the nut of the belt tensioner again to allow the spring to tension the belt again Make sure that the belt tensioner is not seized in its pivot Torque the nut 50 Nm 5 0 kpm 36 ft lbs The belt must be tensioned...

Page 75: ...ly that the belt is installed so that the markings line up NOTE It is not necessary to adjust the marking of the intermediate wheel against the belt marking 193 Turn the belt tensioner to tension the belt and then tighten the Allen head screw Tool width 8 mm The belt must be tensioned at least once per season and be replaced after every 500 hours of operation 194 Method 1 Correct belt tension Turn...

Page 76: ... depressed approx 5 mm 0 2 by normal thumb pressure Tool width 1 2 and 16 mm NOTE Make sure the V belt enters the correct groove on the crankshaft pulley 200 Install the thermostat along with a new gasket in the thermostat housing Then install the thermo stat housing on the engine Tool width 10 mm 201 251DOHC AQ171 Make sure that the O rings on the distributor are not damaged Replace if ne cessary...

Page 77: ... sender wire is not damaged and push on the protective cap 206 Install the intake manifold together with the car buretor Tighten the oil dipstick tube to the intake manifold Tool width 1 2 or 13 mm Then install the hose between the fuel pump and the carburetor 207 251DOHC AQ171 Install the vacuum hoses 1 from the intake manifold and the cold starting de vice and the connection 2 on the magnetic va...

Page 78: ...way The 2 short bolts to be installed up front 212 Install the pipe between the oil cooler and the exhaust manifold Tool width 10 mm Check the sealings Replace if necessary 213 Put new sealings on the cooling water pipes and a new O ring on the heat exchanger and install the heat exchanger to the pipes Assemble the heat exchanger to the thermostat housing Tool width 12 mm 214 Install the heat exch...

Page 79: ...77 215 Install the cooling water hose on the heat ex changer Tighten the hose clamp properly 216 251DOHC AQ171 Install the protective cover over the toothed belt camshaft gear wheels Tool width 10 mm ...

Page 80: ...tributor Tool width 13 mm and the fuel pump Allen head key 6 mm 219 Remove the control bracket ignition coil and the oil trap Tool width 13 mm 220 Remove the starter motor Tool width 19 mm 221 Remove the coolant circulation pump Tool width 10 mm If the pump has been damaged the pump must be replaced as a unit except for the pul ley which can be re used 222 Remove the oil filter Watch out for oil s...

Page 81: ... sender 224 Remove the big nut on the oil cooler Tool width 29 mm Then separate the cooling water tubes from the oil cooler and remove from the en gine 225 Remove the drain cock Tool width 18 mm Clean and flush the cooling water jackets properly ...

Page 82: ...eck also that the spring package including rivets etc and the damper as a whole are free from cracks 228 Remove the center bolt of the pulley and re move the pulley Tool width 24 mm 229 Remove the belt wheel and the inner guide plate from the crankshaft Make sure not to damage the teeth of the belt wheel 230 Remove the cross piece carrier from the inter mediate wheel Make sure that the cross piece...

Page 83: ...seal 233 Lift up the oil pump gear wheel 234 Pull out the intermediate shaft NOTE Make sure that the teeth of the intermediate shaft gear do not damage the bearings in the engine block 235 Remove the pilot bearing locking ring for the in put shaft 236 Use special tool part no 9994090 0 to remove the input shaft bearing Then remove the flywheel Tool width 17 mm 237 Turn the engine upside down Remov...

Page 84: ...Remove the rod bearing caps Tool width 10 mm NOTE The connecting rods and the connecting rod caps are numbered and must not be mixed 242 Push out the pistons from the cylinders using a wooden or plastic handle Let the pistons drop on some sort of soft material to prevent the pistons from being damaged 243 The main bearing caps are marked 1 to 5 counted from the timing gear end of the engine Re mov...

Page 85: ...izes are categorized as ÖD 1 and ÖD 2 When reboring a cylinder the new class must be punched in Pistons 247 Measure the pistons with a micrometer 90 to the gudgeon pin hole and 7 mm 0 2756 from the lower edge Piston diameter standard C marked 95 940 95 950 mm 3 77717 3 77756 D marked 95 950 95 960 mm 3 77756 3 77795 E marked 95 960 95 970 mm 3 77795 3 77835 G marked 95 980 95 990 mm 3 77874 3 7791...

Page 86: ...scraper ring 0 030 0 065 mm 0 00118 0 00256 251 When measuring the piston ring gap the piston ring should be inserted into the cylinder Use a pis ton upside down to correctly position the piston ring Measure the gap with the ring 15 mm 0 591 above the lower edge of the cylinder Use a feeler gauge Upper compression ring 0 30 0 55 mm 0 0118 0 0217 Lower compression ring 0 30 0 55 mm 0 0118 0 0217 Oi...

Page 87: ...ng rod 256 Check the crank bearings and the main bearing journals Measure with a micrometer at several loca tions around the diameter and length The out of round on main and crank bearing journals must not exceed 0 004 mm 0 000157 The taper must not exceed 0 004 mm 0 000157 on any of the jour nals Should the measured values exceed the above given tolerances the crankshaft should be ground to the c...

Page 88: ...is chromium plated The lower compression ring is marked Top Turn the piston rings on the piston so that the gaps are 120 apart from each other 263 Install the bearing shells in the connecting rod and in the caps Oil the cylinder bore piston and the rod bearing Check to make sure that the marking on the piston is facing the timing gear cover when the piston is installed in the cylinder Use a piston...

Page 89: ...worn parts 267 Install the gear wheels and check the gear backlash which should be 0 15 0 35 mm 0 0059 0 0138 268 Check the axial clearance It should be 0 02 0 12 mm 0 00079 0 0047 269 Insert the piston spring guide pin and as semble the lower part of the pump Install new seal rings and the pipe 270 Install new seal rings on the oil pump pipe In stall the pump and the attachment yoke 1 for the dra...

Page 90: ...the spacer rings remain on the drift if the crankshaft is free from wear damage G Knock in the seal ring till the drift bottoms against the crankshaft Use standard drift part no 9991801 273 230 250 AQ131 AQ151 Coat the inside of the flywheel with an anti rust agent Tectyl or its equivalent and install the flywheel Tightening torque 70 Nm 7 0 kpm 51 ft lbs NOTE Always use new bolts 251DOHC AQ171 Tu...

Page 91: ...nd 884599 4 Make sure you know which way the different seal rings are facing prior to removing them Remove the seal ring 1 from the flywheel housing Check the primary shaft 2 and the bearing 3 Should any of them show any signs of damage then remove the lock rings 4 and press out the shaft to gether with the bearing Remove the seal ring 5 and the lock ring 6 from the primary shaft as well as the se...

Page 92: ...ue 10 Nm 1 0 kpm 7 5 ft lbs 284 Grease the crankshaft seal abundantly and use special tool part no 9995283 0 to install it NOTE A If the old seal ring has not left a wear surface on the crankshaft the seal should be pressed in edge to edge with the flange B Should the old seal ring have left a wear mark on the crankshaft the new seal ring is pressed in until the mark on the tool is edge to edge wi...

Page 93: ...stall the cylinder head see page 58 para graphs 129 133 and pages 70 72 paragraphs 183 190 for 230 250 AQ131 AQ151 and pages 68 70 paragraphs 167 182 as well as page 73 paragraphs 191 195 for 251DOHC AQ171 Then remove the nut and the washer on the belt tensioner alternatively the screw on 251DOHC AQ171 and install counter hold part no 9995284 8 Install the thick washer on the pulley and tighten th...

Page 94: ...t a new seal ring on the pump and a new gasket on the engine block Push the pump up wards against the cylinder head and tighten the screws and the nuts 293 Install the pulley on the circulation pump Then install the toothed belt sea water pump alternator and the V belt 294 Install the cylinder head See under chapter 4 ...

Page 95: ...nstall the valve cover and the plate for the belt marking Make sure that the belt marking coincides with the recess of the plate Adjust if necessary 297 Remove the distributor cap 298 Turn the rotor so that the marking on the rotor is pointing approx 60 away from the marking in the distributor 299 Push the distributor down into its location in the engine block and make sure that the rotor lines up...

Page 96: ...by loosening the screw 6 Tighten the new condenser and connect the flat terminal Push on the rotor and install the distributor cap NOTE During the test run check the dwell angle and adjust if necessary See under Technical Data 302 Install the bracket for the ignition coil on the en gine 303 Install the fuse bracket and the wiring harness Clamp the wiring harness to the flywheel housing and tighten...

Page 97: ...k that the passage in the drain cock 6 is not clogged Install the insert in the housing and install the O rings on the insert Replace the O rings if neces sary Install the end covers and tighten them by the center screw Replace the O ring 7 should it be damaged Check and replace the O ring 8 if neces sary 308 Install a new O ring and install the oil cooler on the engine but do not tighten it 309 C...

Page 98: ...er the protective rubber cap 1 Also clamp the wire to the cooling water pipe 2 313 Oil the gasket of the oil filter and install the fil ter by hand until the rubber gasket touches the en gine block Then turn the filter by hand a further 1 2 turn Check the oil pressure and also for leakages around the oil filter during the first test run ...

Page 99: ...97 References to Service Bulletins Group No Date Regarding ...

Page 100: ...98 Notes ...

Page 101: ...of this page write your comments down and post it to us The address is at the bottom of the page We would prefer you to write in English or Swedish From Refers to publication Publication no Issued Suggestion reasons Date Name AB Volvo Penta Customer Support Dept 42200 SE 405 08 Gothenburg Sweden ...

Page 102: ...7732007 5 English 05 1999 ...